SiC (silicon carbide) is expected as a material for a next-generation semiconductor device. SiC have excellent physical properties in comparison with Si (silicon). A band gap is three times, breakdown electric field strength is approximately ten times, and thermal conductivity is approximately three times. A low loss semiconductor device which can operate at a high temperature can be realized by using such properties.
However, for example, in the case where a metal insulator semiconductor (MIS) structure is formed by using SiC, an interface state density between a semiconductor and an insulating layer increases in comparison with a case where Si is used. Therefore, there is a problem that mobility of an electric charge is lowered, and ON-resistance of a metal insulator semiconductor field effect transistor (MISFET) and an insulated gate bipolar transistor (IGBT) is increased. Further, for example, in the case where a Schottky barrier diode (SBD) is manufactured by providing a metal electrode on SiC, fermi level pinning is caused by an interface state between the SiC and the metal electrode. Therefore, there is a problem that desired properties as an SBD cannot be realized.